OBJECTIVE: This study evaluated the early effectiveness of isolated pectoralis minor tenotomy (PMT) in the surgical treatment of selected patients with neurogenic thoracic outlet syndrome (NTOS) compared with supraclavicular decompression (SCD; as scalenectomy, neurolysis, and first rib resection) plus PMT (SCD+PMT). METHODS: Data were obtained for 200 patients undergoing operative treatment for disabling NTOS between 2008 and 2011. Isolated PMT was offered to 57 patients with physical examination findings limited to the subcoracoid space, and SCD+PMT was offered to 143 with scalene triangle and subcoracoid findings. Functional outcomes were assessed before and 3 months after surgery using the Disabilities of the Arm, Shoulder and Hand (DASH) survey and related instruments. RESULTS: There were no significant differences (P > .05) between PMT and SCD+PMT patients with respect to age (overall, 37 ± 1 years), sex (73% women), side affected (52% right, 14% bilateral), or the frequency of various NTOS symptoms, but fewer PMT patients had a bony anomaly (0% vs 18%; P < .01) or a history of injury (35% vs 61%; P < .01). Mean preoperative DASH scores were similar between PMT and SCD+PMT groups (49.9 ± 3.6 vs 50.8 ± 1.6), but previous use of opiate pain medications was higher in PMT patients (47% vs 20%; P = .0004). PMT was conducted as an outpatient procedure, whereas the mean hospital stay after SCD+PMT was 4.8 ± 0.1 days, with two patients (1%) requiring early reoperations for persistent lymph leaks. Mean DASH scores 3 months after surgery were significantly improved after isolated PMT (29.6 ± 4.2; P < .01) and SCD+PMT (41.5 ± 2.2; P < .01), but the mean extent of improvement in DASH scores was not significantly different in PMT (32% ± 9%) vs SCD+PMT (19% ± 5%). There were also no significant differences in the proportion of PMT vs SCD+PMT patients demonstrating improvement in functional outcome measures (75% vs 72%) or in overall use of opiate medications (35% vs 27%). CONCLUSIONS: Isolated PMT is a low-risk outpatient procedure that is effective for the treatment of selected patients with disabling NTOS, with early outcomes similar to SCD+PMT. These findings emphasize the importance of recognizing subcoracoid brachial plexus compression as part of the spectrum of NTOS and support the role of PMT in surgical management.